Problem: Jessica decided to paint some of the rooms at her 18-room inn, Jessica's Place. She discovered she needed $\frac{4}{5}$ of a can of paint per room. If Jessica had 12 cans of paint, how many rooms could she paint?
We can divide the cans of paint (12) by the paint needed per room ( $\frac{4}{5}$ of a can) to find out how many rooms Jessica could paint. $ \dfrac{{12 \text{ cans of paint}}} {{\dfrac{4}{5} \text{ can per room}}} = {\text{ rooms}} $ Dividing by a fraction is the same as multiplying by the reciprocal. The reciprocal of ${\dfrac{4}{5} \text{ can per room}}$ is ${\dfrac{5}{4} \text{ rooms per can}}$ $ {12\text{ cans of paint}} \times {\dfrac{5}{4} \text{ rooms per can}} = {\text{ rooms}} $ ${\dfrac{60}{4}\text{ rooms}} = 15\text{ rooms}$ Jessica could paint 15 rooms.